Method and apparatus for coupling a voiceband modem circuit to a common phoneline connector
First Claim
1. A method of coupling a device operating at voiceband frequencies in parallel with a device operating at frequencies above voiceband comprising:
- inserting at an input interface between the device operating at voiceband frequencies and the device operating at frequencies above voiceband a series pair of inductors, a first inductor of the series pair having a low inductance and a high self-resonant frequency and a second inductor of the series pair having a high inductance and low self-resonant frequency, the low inductance, the high self-resonant frequency, the high inductance and the low self-resonant frequency being each determined to locate a filtering cutoff point between the voiceband frequencies and the frequencies above voiceband.
6 Assignments
0 Petitions
Accused Products
Abstract
A method and apparatus for coupling a voiceband modem circuit to a common phoneline connector, the common phoneline connection having a ring line connection and a tip line connection which couples a ring/tip line pair to a subscriber loop circuit, the voiceband modem circuit operating in a voiceband modem operating frequency band and having a voiceband modem interface ring line and a voiceband modem interface tip line. The voiceband modem interface ring line is coupled to the ring line and the voiceband modem interface tip line is coupled to the tip line connection by inserting, between the ring line connection and the voiceband modem interface ring line and between the tip line connection and the voiceband modem interface tip line, a series pair of inductors. A first inductor of the series pair has a low inductance and a high self-resonant frequency and a second inductor of the series pair has a high inductance and low self-resonant frequency. The low inductance, the high self-resonant frequency, the high inductance and the low self-resonant frequency are each determined to locate a filtering cutoff point between the voiceband modem operating frequency band and a digital subscriber line operating frequency band.
7 Citations
12 Claims
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1. A method of coupling a device operating at voiceband frequencies in parallel with a device operating at frequencies above voiceband comprising:
inserting at an input interface between the device operating at voiceband frequencies and the device operating at frequencies above voiceband a series pair of inductors, a first inductor of the series pair having a low inductance and a high self-resonant frequency and a second inductor of the series pair having a high inductance and low self-resonant frequency, the low inductance, the high self-resonant frequency, the high inductance and the low self-resonant frequency being each determined to locate a filtering cutoff point between the voiceband frequencies and the frequencies above voiceband. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An interface circuit between a device operating at voiceband frequencies in parallel with a device operating at frequencies above voiceband comprising:
a series pair of inductors coupled between an input of the device operating at voiceband frequencies and an input of the device operating at frequencies above voiceband, a first inductor of the series pair having a low inductance and a high self-resonant frequency, and a second inductor of the series pair having a high inductance and low self-resonant frequency, the low inductance, the high self-resonant frequency, the high inductance and the low self-resonant frequency, being each determined to locate a filtering cutoff point between the voiceband frequencies and the frequencies above voiceband. - View Dependent Claims (8, 9, 10, 11, 12)
Specification